August 05, 2014

Ebola mortality rate expected to rise

The death rate so far in the world's worst outbreak of Ebola is not as extreme as recorded in the past, but experts expect it to prove no less virulent in the end, once more victims succumb and the grim data is tallied up.

Latest figures from the World Health Organization (WHO) record 1,603 cases of Ebola in the West African outbreak and 887 deaths - giving a death rate of just over 55 percent.

That is well below the 78.5 percent average death rate over 14 past outbreaks of the same virus - called the "Zaire strain" after the former name of the Democratic Republic of Congo where it was first detected in 1976.

In some outbreaks the rate was up to 90 percent, according to WHO data.

Experts say death rates for Ebola outbreaks can rise as the disease runs its course, which is what they now expect.

"This is partly a statistical thing about collecting death events, and also partly about the maturity of the outbreak," said Derek Gatherer, a virologist at Britain's University of Lancaster who has been following the outbreak since it started in February.

"The nearer we get to the end of the epidemic, the closer we would expect the fatality rate to correspond to the Zaire Ebola average of 80 percent," he told Reuters.

Ebola can take up to a month to kill its victims, said Ben Neuman, an expert in viruses at Britain's Reading University.

Already, the death rate in Guinea, where the infection was first detected, has reached 74 percent. The overall regional outbreak mortality figure is brought down by lower death rates in countries that were more recently hit: 54 percent in Liberia and around 42 percent in Sierra Leone.

"It will take a few weeks until we see the outcome of a wave of new cases like this one," Neuman said. "(The) Ebola fatality rates look particularly low in Sierra Leone at the moment compared to Guinea, because the virus only recently arrived."

There is still some hope that the rise in death rates can be slowed through medical care. Neuman noted that when doctors are able to begin treatment soon after infection, the survival rates from Ebola can increase significantly.

But even at 50 to 60 percent mortality, no other human disease comes close to Ebola's ability to kill those it infects, specialists say.

The corner of West Africa stricken by Ebola is among the poorest areas in the world and government hospitals in the region often lack even basic equipment, with dirty and overcrowded rooms.

Fear of being left to die in isolation and suspicion of doctors in masks and full body protective suits is driving some patients to evade treatment altogether, meaning they can go uncounted in the data whether they live or die.

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The death rate so far in the world's worst outbreak of Ebola is not as extreme as recorded in the past, but experts expect it to prove no less virulent in the end, once more victims succumb and the grim data is tallied up.

Latest figures from the World Health Organization (WHO) record 1,603 cases of Ebola in the West African outbreak and 887 deaths - giving a death rate of just over 55 percent.

That is well below the 78.5 percent average death rate over 14 past outbreaks of the same virus - called the "Zaire strain" after the former name of the Democratic Republic of Congo where it was first detected in 1976.

In some outbreaks the rate was up to 90 percent, according to WHO data.

Experts say death rates for Ebola outbreaks can rise as the disease runs its course, which is what they now expect.

"This is partly a statistical thing about collecting death events, and also partly about the maturity of the outbreak," said Derek Gatherer, a virologist at Britain's University of Lancaster who has been following the outbreak since it started in February.

"The nearer we get to the end of the epidemic, the closer we would expect the fatality rate to correspond to the Zaire Ebola average of 80 percent," he told Reuters.

Ebola can take up to a month to kill its victims, said Ben Neuman, an expert in viruses at Britain's Reading University.

Already, the death rate in Guinea, where the infection was first detected, has reached 74 percent. The overall regional outbreak mortality figure is brought down by lower death rates in countries that were more recently hit: 54 percent in Liberia and around 42 percent in Sierra Leone.

"It will take a few weeks until we see the outcome of a wave of new cases like this one," Neuman said. "(The) Ebola fatality rates look particularly low in Sierra Leone at the moment compared to Guinea, because the virus only recently arrived."

There is still some hope that the rise in death rates can be slowed through medical care. Neuman noted that when doctors are able to begin treatment soon after infection, the survival rates from Ebola can increase significantly.

But even at 50 to 60 percent mortality, no other human disease comes close to Ebola's ability to kill those it infects, specialists say.

The corner of West Africa stricken by Ebola is among the poorest areas in the world and government hospitals in the region often lack even basic equipment, with dirty and overcrowded rooms.

Fear of being left to die in isolation and suspicion of doctors in masks and full body protective suits is driving some patients to evade treatment altogether, meaning they can go uncounted in the data whether they live or die.